What do you do after a hard day in the classroom? Tinker in the potting shed? Chill out with a glass of wine? Or how about refining the prototype of your recently patented invention? It's not an average hobby but, then again, there's nothing average about people whose belief in a product is so great they will throw tens of thousands of pounds at it to ensure its success in the marketplace.
Five years ago, Elaine Stephen came up with an idea for a flexible harness which would help keep groups of young children safe on school trips. She christened it Walkodile and convinced John, her husband, that they should commit pound;20,000 to getting the idea into production.
"The only time I have felt vulnerable in my 23 years of teaching is when I take the children out," says Elaine, 43, a Year 1 teacher at Buchanhaven School in Peterhead, Aberdeenshire. "Walkodile was something I came up with which I thought would keep my children safe. I never thought I was going to invent something. I just thought it would help me do my job."
Neither did she envisage paying out pound;20,000 for making the Walkodile prototype, pound;40,000 on patenting it and a further pound;50,000 on metal moulds for mass production.
And that's just the tip of the iceberg: there was also the pound;23,000 spent on a prototype which was badly put together, money for research and for product design at Leicester's De Montfort University, plus tests at Loughborough University's Ergonomic and Safety Research Institute.
That's all before fees for lawyers, IT consultants and PR companies.
"Before you know what you're doing, you're on a rollercoaster ride," says Elaine, whose husband is now the full-time promoter of his wife's brainchild. Thank goodness for a close family. Elaine's sister and brother came up with pound;60,000 backing; Elaine and John a further pound;100,000 by remortgaging their house, selling shares and insurance policies and selling a house they owned in Florida.
Winning first prize in the Shell Safety Exchange competition in 2005 netted them a further pound;15,000.
Walkodile, a flexible spine with clips forJeither four or six children which connects them together, finally went on sale in December and is doing well. So far, 250 have sold at pound;199 each and Elaine is in talks with nursery chains about stocking them. But she is aware of the financial risk involved. That's why she insists on teaching five days a week in the same school she attended as a child.
"There's potential for us to do very well out of this," she says.
"That will be the realisation of the dream," adds John, who worked for Shell and BP before becoming a property developer. "We've lost count of the times people have said, 'You will be millionaires soon - it's got global potential'.
"But we never anticipated having to do all we've done. We never anticipated spending hours talking about the minutest detail of a clip or travelling all over the country."
According to the Patent Office, soon to be renamed the UK Intellectual Property Office, fewer than one in four new products is granted a patent and the process takes, on average, between two to three years.
Trevor Baylis, inventor of the wind-up radio, says it takes true grit to embark on the lonely journey from invention to marketplace. "Inventors aren't fruitcakes. They're ordinary men and women who change our lives,"
says the man who set up Baylis Brands to protect and advise lone inventors.
"There's an invention in all of us and I respect anyone who has the guts to get off their backside and give it a go."
James Dyson, creator of the vacuum cleaner, says. "The easy bit is having the idea. You have to be committed enough to keep your idea going despite financial hardship and ridicule."
So what does it take to become an inventor? According to Trevor, it's an ego the size of a truck and the ability not to blab about your idea down the pub.
James says it's doggedness and having a quizzical and critical mind. And if you have an idea? "Trust your instincts," he says. "Don't give up if people scoff at it. I think a lot give up just as they are about to be successful."
There is no chance of Elaine and John doing that. "We still believe absolutely passionately in Walkodile," says John. But there have been sleepless nights.
"We have two types of day: the Paula Radcliffe crying on the pavement kind, when we're talking to banks and lawyers or managing cash flow," says John.
"And the Kelly Holmes type, when we go to schools and nurseries and we get fantastic feedback. When I first saw Walkodile being used in London, it was amazing to see something which had come from Elaine's head that was now a living, breathing reality on the streets of the capital."
But Elaine is not planning an early retirement yet.
"This has been a huge learning curve for us and I take my hat off to people who did this and have been very successful. I now know the journey they have been on.
"I'm quietly confident but you never, ever know"
Emily Daly came up with her Talking Dice game in 2001 to boost the oral skills of pupils learning foreign languages at her school in Cardiff.
"I felt, and still feel, that speaking skills are underdeveloped, even at GCSE," says Emily, a former language teacher at Llanishen Comprehensive School.
"Part of the problem is that pupils are not required to be spontaneous in their speech."
Emily decided to cover dice with pictures and get students to construct sentences using what appeared when the dice were thrown. This forced youngsters to think of sentences off the top of their heads. The idea was a success and soon other teachers wanted to use the dice.
Initially, Emily bought plain dice and stuck on her own pictures, which related to five different topics.
Within two years of coming up with the idea, she had given up teaching and was running her Talking Dice business full-time, travelling all over Europe and learning how to draw up business plans.
She was supported by two entrepreneurial organisations which were backed by the Welsh Assembly and local businessman Gareth Jones was her mentor for three years.
"It was a very exciting few years. I travelled all over the place and learnt a lot of skills," says Emily, 44. "One of the highlights was when we got an order from Saudi Arabia."
Sadly, she was diagnosed with multiple sclerosis and was forced to sell Talking Dice last year to friend and colleague Vanessa Parle-Smith. But the business is still close to her heart, with Talking Dice being used all over Europe and set to break into the American market.
Emily now works as a part-time foreign languages advisor for Cardiff council.
Her advice for other inventors? "Always maintain a sense of humour and keep realistic. You so badly believe in what you've got but you've got to come down from that and not be so personal about it. In that way, when the knocks come, they're not going to hit you quite so hard."
And does she consider herself an inventor, a teacher or a businesswoman? "I'm a melting pot of the lot, I suppose," says Emily. "But I'm an ideas person really. I've still got lots of them."
Janet Hill is happy to admit that wall displays in her classroom left a lot to be desired. "I used to put up awful displays," says Janet, 37, of Twickenham, south-west London. "Even colleagues would come and have a laugh at them."
This prompted her to think there was a market for ready-made display packs to tie in with national curriculum topics.
"I started messing about with it in 2003 when I was on maternity leave,"
says Janet, who enlisted the help of Tammy Scott-Cree, an artist friend and fellow teacher, to help her design the display kits.
"I had a feeling there was a need for this product and I wanted to get it out there before someone else did," says Janet. "I sat down and drew up a wish list of what would help teachers."
She now produces packs on historical topics such as ancient Egypt, ancient Greece, the Victorian era and composers. In science, she covers topics ranging from electricity and sounds to plants and keeping healthy.
Janet is now working on a display which can be used for modern language teaching, including Mandarin.
"The packs are so much more than displays - they really help a teacher to deliver a topic. Everything has been researched, the brainwork has been done and the children love them," she says.
The display can be changed as they go through the topic and pupils' own artwork and research can be added. The packs also include laminated brain-teaser cards which allow pupils to carry out extra work on their own.
Janet's is very much a cottage industry. "I can print up to A3 size at home and I pay someone pound;6 an hour for laminating," says Janet, a mother of three who teaches Year 4 two days a week at St James Roman Catholic Primary School in Twickenham. She has her own website and also sells through Teaching Trends, a shop selling educational resources in East Finchley.
"I'd like the business to be bigger," says Janet. "The next big step would be to pay a printer to print 1,000, but I don't feel I'm ready for that yet."
Running the business from home, Janet has sold more than 200 packs so far and she is now in discussion with Knowsley education authority, which is considering using the packs in their primary schools.